Portal de Periódicos da CAPES

Long-Range Structural Order, Moiré Patterns, and Iridescence in Latex-Stabilized Foams

2006; American Chemical Society; Volume: 128; Issue: 24 Linguagem: Inglês

10.1021/ja060640n

1943-2984

Syuji Fujii, Anthony J. Ryan, Steven P. Armes,

Proteins in Food Systems

We describe the facile production of highly stable foams stabilized solely by micrometer-sized, sterically stabilized polystyrene (PS) latex particles. Such foams can survive for more than one year in the wet state and remain intact after drying. In contrast, foams stabilized with either sodium dodecyl sulfate or poly(N-vinylpyrrolidone) were destroyed after removal of the aqueous phase. Scanning electron microscopy studies reveal hexagonally close-packed arrays of PS particles within the dried foam, which suggests high colloid stability for the PS particles prior to their adsorption at the air-water interface. Localized moiré patterns are observed by optical microscopy due to the formation of well-defined latex bilayers with exquisite long-range order. Moreover, the dried foams are highly iridescent in bright transmitted light, which may offer potential applications in security inks and coatings.